CN110447141A - Device and method for activated batteries monomer - Google Patents

Abstract

The present invention relates to a kind of methods for activated batteries monomer, the battery cell includes anode, nickel cobalt manganese (NCM) positive electrode for wherein adding or being mixed with lithium nickel oxide (LNO) is applied in the anode, this method includes the steps that the step of being charged to battery cell and being discharged battery cell, wherein, in the step of charging to battery cell, state of the battery cell from the temperature for being heated to 45-60 DEG C, the charging of the C- rate with 0.1-0.5C.In the activation of the invention with these features, the extruding/heating condition for inhibiting gas to generate is provided, therefore protuberance caused by generating due to gas, cell deformation and performance deterioration can be prevented.

Description

Apparatus and method for activating battery cells

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Korean Patent Application No. 10-2017-0163720 filed on Nov. 30, 2017, the entire contents of which are incorporated herein by reference.

technical field

The present invention relates to an apparatus and method for activating a battery cell, and more particularly, the present invention relates to an apparatus and method for activating a battery cell: heat (and/or pressure) is applied to the battery cells to reduce activation time and gas generation during the activation process.

Background technique

In recent years, the demand for secondary batteries as an energy source is rapidly increasing with technological development and increasing demand for mobile devices. Depending on the type of external device, such a secondary battery may be used in the form of a single battery cell, or in the form of a battery module in which a plurality of unit cells are electrically connected to each other. For example, small devices such as mobile phones utilize the output and capacity of one battery cell to operate for a predetermined time. On the other hand, for medium or large devices such as notebook computers, portable DVDs, personal computers, electric vehicles, hybrid electric vehicles, etc., battery modules including a large number of battery cells need to be used due to their output and capacity issues.

Such a secondary battery is manufactured through a process of assembling a battery cell and a process of activating the battery. Here, the battery activation process is generally performed by applying a necessary current to the battery cells to be charged/discharged through a charge/discharge device including a positive electrode contact device and a negative electrode contact device.

As shown in FIG. 1 , the charging/discharging apparatus for a secondary battery includes: a tray 20 into which battery cells 10 are respectively accommodated or fitted to be fixed; and contact devices 30 and 40 , which contact devices 30 and 40 are connected to the positive electrode 11 and the negative electrode 12 of each battery cell 10 fixed to the tray 20 to charge/discharge the battery cell 10 . The contact devices 30 and 40 may have a structure including contact pins 31 and 41 arranged such that the tray 20 is interposed therebetween so as to be electrically connected to the positive electrode 11 or the negative electrode 12 .

Nickel (Ni)-based NCM cathode materials (NiCoMn: nickel cobalt manganese cathode materials) are widely used due to their high energy density, long life, and durability. In addition, LNO (LiNiO ₂ : lithium nickel oxide) may be added to increase the lithium content to further increase the energy density.

However, there is a problem in that gas is generated in the battery cell due to the phase transition of the LNO in a state where the unreacted lithium by-product remains in the raw material required for the production of LNO.

The gas generated in the battery cell may act as a resistance or cause deformation of the battery module and the battery pack, so the failure rate of the product increases. In particular, in the case of a pouch-type secondary battery having a relatively soft case, rather than a can-type secondary battery having a relatively rigid case, deformation due to gas generation is more serious.

SUMMARY OF THE INVENTION

technical problem

Therefore, in order to solve the above-mentioned problems, it is an object of the present invention to provide an apparatus and method for activating a battery cell in which gas is generated to a minimum degree in a positive electrode coated with a nickel-cobalt-manganese positive electrode material, the nickel-cobalt The manganese cathode material is added or mixed with lithium nickel oxide (LNO).

Technical solutions

In order to achieve the above objects, the present invention provides a method for activating a battery cell, which activates a battery cell including a positive electrode coated with a nickel-cobalt-manganese (NCM) positive electrode material, and lithium nickel oxide (LNO) is Adding or mixing into the nickel-cobalt-manganese (NCM) positive electrode material, the method comprises: the step of charging the battery cells; and the step of discharging the battery cells, wherein, in the step of charging the battery cells, The battery cells are charged under a charging condition of a C-rate of 0.1C to 0.5C in a state of being heated at a temperature of 45°C to 60°C.

In more detail, the battery cell may be charged under a charging condition of a C-rate of 0.2C in a state of being heated at a temperature of 45°C to 60°C.

The battery cells can be charged in a fully discharged state at a charge rate of 0%, and

The first pressure applied to the battery cells during the first charging interval and the second pressure applied to the battery cells during the second charging interval are different, the first charging interval being determined from 0% The second charging interval is determined by the charging rate from the reference charging rate to 100%, wherein the second pressure may be higher than the first pressure.

In this embodiment of the present invention, the first pressure is set to a pressure of less than 0.1 kgf/cm ² , and the second pressure is set to a pressure of 0.1 kgf/cm ² to 0.5 kgf/cm ² .

Also, the reference charging rate is set within a range of a charging rate of 10% to 20%, and more particularly, the reference charging rate is set within a range of a charging rate of 15% to 19%.

In addition, the present invention also provides an apparatus for activating a battery cell. The apparatus for activating a battery cell activates a battery cell comprising a positive electrode coated with a nickel-cobalt-manganese (NCM) positive electrode material to which lithium nickel oxide (LNO) is added or mixed material, and the apparatus includes: a heating plate fitted between two or more stacked battery cells to heat the battery cells; and a pressing device, the pressing The device presses the battery cells in the stacking direction to apply pressure to each of the battery cells.

The heating plate can squeeze and heat the battery cells at the same time to provide both functions at the same time. That is, the pressing device may not be provided separately, but may be combined with the heating plate.

Furthermore, the apparatus may further include a thermometer that measures the temperature of the battery cell heated by the heating plate and a pressure gauge that measures the pressure applied to the battery cell by the pressing device.

favorable effect

When the activation process is performed according to the present invention having the above-described configuration, pressing/heating conditions for suppressing gas generation can be provided to prevent bulging, battery deformation, and performance deterioration due to gas generation.

That is, even if LNO is added to nickel (Ni)-based NCM cathode materials to improve performance, the conventional problems due to gas generation can be solved.

Description of drawings

FIG. 1 is a simplified schematic diagram of an activation device according to the related art.

Fig. 2 is a simplified diagram of the activation apparatus according to the present invention for illustrating the state in which the pressing device is integrated with the heating plate.

FIG. 3 is a simplified schematic diagram illustrating a state in which the heating plate and the pressing device are separated from each other.

4 is a graph illustrating that the capacity retention ratios C3 and C6 of the battery cells activated according to the activation method of the present invention are higher than the capacity retention ratio C1 of the battery cell according to the related art.

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the technical idea of the present invention. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

In order to clearly illustrate the present invention, parts irrelevant to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

Also, the terms or words used in this specification and the claims should not be construed restrictively in ordinary meanings or dictionary-based meanings, but should be described and described in the best way based on the concept that the inventor can properly define the terms. The principles explaining his or her invention are to be interpreted as meanings and concepts consistent with the scope of the invention.

The present invention relates to an apparatus and method for activating a battery cell in which an electrode assembly and an electrolyte are inserted/injected into a case, and provides that compared with the structure according to the related art, it is possible to reduce Apparatus and method for generation of internal gas and reduction of activation time. In particular, according to the present invention, when a nickel-cobalt-manganese (NCM) positive electrode material, to which lithium nickel oxide (LNO) as a positive electrode active material is added or mixed, is applied to the positive electrode constituting the electrode assembly, more can be achieved Effect. Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

Example 1

2 and 3 , the apparatus for activating battery cells according to Embodiment 1 of the present invention includes: a tray 20 into which the battery cells 10 are accommodated or fitted, respectively, to be fixed; and contact devices 30 and 40 , the contact devices 30 and 40 are connected to the positive electrode 11 and the negative electrode 12 of each battery cell 10 fixed to the tray 20 to charge/discharge the battery cell 10, and the apparatus further includes: a heating plate 50, The heating plate 50 is fitted between two or more stacked battery cells 10 to heat the battery cells 10; and a pressing device 60 pressing the battery cells in the stacking direction body 10 to apply pressure to each battery cell 10 .

Here, the heating plate 50 may simultaneously perform two functions of pressing and heating the battery cells 10 according to a desired design. That is, the pressing device 60 may not be provided separately but combined with the heating plate 50 .

For example, as shown in FIG. 2 , the heating plate 50 combined with the pressing device 60 may operate in such a manner that the heating plate 50 and the battery cells 10 are alternately arranged adjacent to each other with the heating plate 50 . The thickness of the battery cell 10 is increased, and the battery cell 10 is squeezed.

Alternatively, as shown in FIG. 3 , the pressing device 60 applies a force in the direction of the other side to the heating plate 50 or the battery cell 10 arranged at the outermost side, so that the entire battery cell 10 is Squeeze simultaneously. Here, pressure may be applied to all the battery cells 10 . For reference, since the above-described manner in which the thickness of the heating plate 50 is increased is complicated in configuration, the manner in which the entire battery cell 10 is arranged at the outermost side is simple in configuration and advantageous in operability. The pressing device 60 is moved in the direction of the other side, so that all the entire battery cells 10 are pressed simultaneously.

Here, the heating of the heating plate 50 may be performed by well-known heating wires, heating elements, or the like. The pressing of the heating plate 50 and/or pressing device 60 may be performed by well-known coupling to hydraulic, pneumatic, electronic means or the like.

Even in the configuration in which the pressing device 60 is separated, the heating plate 50 may be arranged between the corresponding battery cells 10 in the same configuration, and when the pressing device 60 is operated, the tray 20 may be deformed to prevent the occurrence of interference.

In addition, in this embodiment, a thermometer (not shown) for measuring the temperature of the battery cell 10 heated by the heating plate 50 and a pressure gauge (not shown) may be further provided, and the pressure gauge is used for For measuring the pressure applied to the battery cell 10 by the pressing device 60 .

Thermometers and pressure gauges can continuously provide information to a controller (not shown) of the heating plate (and extrusion device). The controller can receive this information to control the heating plate (and pressing device) to apply the desired temperature and pressure of the battery cells 10 .

In addition, the apparatus may further include an air conditioner that cools the heated battery cells 10 and rapidly discharges the heated air.

Example 2

Furthermore, the present invention provides a method for activating the battery cell 10 by using the above-described activation device.

The method according to Embodiment 2 of the present invention is a method for activating a battery cell including a positive electrode coated with a nickel-cobalt-manganese (NCM) positive electrode material to which lithium nickel oxide (LNO) is added or mixed into the nickel cobalt manganese (NCM) cathode material. The method includes the steps of charging the battery cells 10 and discharging the battery cells 10 . The charging step and the discharging step are repeatedly performed at least once or at least twice. In the step of charging the battery cell 10, the battery cell 10 is charged under the following charging conditions: in a state of heating at a temperature of 45°C to 60°C, at a C-rate of 0.1C to 0.5C to charge. For reference, 1C-rate means the amount of current used when the cell is fully charged for 1 hour, 0.1C means the amount of current the cell is fully charged when charged for 10 hours, and 0.5C means the amount of current used when charged for 2 The amount of current at which a battery cell is fully charged in hours.

In more detail, the battery cell 10 may be charged in a state of being heated to a specific temperature of 45° C. to 60° C. under a charging condition of a C-rate of 0.2 C (the battery cell is fully charged when charging for 5 hours). current flow).

In this embodiment, the battery cells 10 can be charged in a fully discharged state at a charge rate of 0%. When charging, a pressure for pressing the battery cells 10 is additionally applied (using an activation device including the above-described members). The pressure is divided into a first pressure applied to the battery cells during a first charging interval determined from a 0% charge rate to a reference charge rate and a second pressure, the second pressure being applied from the reference charge rate The charging rate to 100% is applied to the battery cells during the second charging interval determined by the charging rate.

Here, the second pressure is higher than the first pressure. In this embodiment of the present invention, the first pressure is set to a pressure of less than 0.1 kgf/cm ² , and the second pressure is set to a pressure of 0.1 kgf/cm ² to 0.5 kgf/cm ² .

Also, the reference charging rate is set within a range of a charging rate of 10% to 20%, and more particularly, the reference charging rate is set within a range of a charging rate of 15% to 19%.

As described above, the battery cells are fully charged from a 0% charge rate to a 100% charge rate, and then the battery cells are discharged at a 70% charge rate to adjust the charge rate at a 30% charge rate. That is, a battery cell charged at a charge rate of 100% is discharged at a charge rate of 30%, and then aged under predetermined temperature and humidity conditions. That is, when charging and discharging are performed under the above-described conditions so that a solid electrolyte interphase layer is formed in the battery cell, an aging step of stabilizing the activated battery cell as a post-process is performed. Here, the aging step is performed in the same manner as the aging process according to the related art.

It has been confirmed that the capacity retention ratio of the battery cell activated by the method of the present invention (the capacity of how much capacity remains when the battery cell is left at a specific temperature for a specific period of time) is higher than that of the battery cell activated by the method according to the related art. capacity retention.

That is, in FIG. 4 , C1 represents a battery subjected to aging at room temperature and high temperature in a state of being charged to a specific value at a charge rate of 20% to 40% at a charge condition of a C-rate of 0.1 C at room temperature The capacity retention rate of the monomer, C3 represents the state of heating at a temperature of 35° C. to 45° C. according to the embodiment of the present invention, under the charging condition of the C-rate of 0.2 C at a charge rate of 100%, and then at a charge rate of 20% The capacity retention rate of a battery cell discharged to a charge rate of 40% for aging at room temperature and high temperature, and C6 represents the state of heating at a temperature of 50°C to 70°C according to an embodiment of the present invention, at a C of 0.2C - Capacity retention rate of a battery cell charged at a charge rate of 100% and then discharged at a charge rate of 20% to 40% for aging at room temperature and high temperature under high-rate charging conditions.

As shown in the graph of FIG. 4 , it was confirmed that the capacity retention ratio (%) of the battery cell realized by the activation method according to the present invention was higher than the capacity retention ratio (%) of the battery cell realized by the activation method according to the related art %). Also, in the activation method of the present invention, since the battery cell is in a pressed state (deviation from the gas generation condition), an effect of suppressing gas generation can be expected compared with the method according to the related art.

That is, when the activation process is performed according to the present invention having the above-described configuration, pressing/heating conditions for suppressing gas generation can be provided to prevent swelling, battery deformation, and performance degradation due to gas generation. In particular, even if LNO is added to nickel (Ni)-based NCM cathode materials to improve performance, the conventional problems due to gas generation can be solved.

While embodiments of the present invention have been described with reference to specific embodiments, it will be apparent to those skilled in the art that, without departing from the spirit and scope of the invention as defined in the following claims, Various changes and modifications.

Claims (11)

1. A method for activating a battery cell comprising a positive electrode coated with a nickel cobalt manganese (NCM) positive electrode material to which lithium nickel oxide (LNO) is added or mixed In the nickel-cobalt-manganese (NCM) cathode material, the method includes: the step of charging the battery cells; and the step of discharging the battery cell, Wherein, in the step of charging the battery cells, the battery cells are charged under a charging condition of a C-rate of 0.1C to 0.5C in a state of being heated at a temperature of 45°C to 60°C . 2 . The method of claim 1 , wherein the battery cell is charged under a charging condition of a C-rate of 0.2 C in a state of being heated at a temperature of 45° C. to 60° C. 3 . 3. The method of claim 1 or 2, wherein the battery cell is charged in a fully discharged state at a charge rate of 0%, and The first pressure applied to the battery cells during the first charging interval and the second pressure applied to the battery cells during the second charging interval are different, the first charging interval being determined from 0% A charging rate to a reference charging rate is determined, and the second charging interval is determined by a charging rate from the reference charging rate to 100%. 4. The method of claim 3, wherein the second pressure is higher than the first pressure. 5. The method of claim 4, wherein the first pressure is set to a pressure of less than 0.1 kgf/cm ² , and the second pressure is set to 0.1 kgf/cm ² to 0.5 kgf/ cm ² pressure. 6. The method of claim 3, wherein the reference charging rate is set in a range of a charging rate of 10% to 20%. 7. The method of claim 6, wherein the reference charging rate is set in a range of a charging rate of 15% to 19%. 8. The method according to any one of claims 3 to 7, further comprising the step of discharging the battery cells charged at a charge rate of 100% at a charge rate of 20% to 40%, and at a charge rate of 20% to 40% The battery cells are aged under predetermined temperature and humidity conditions. 9. An apparatus for activating a battery cell comprising a positive electrode coated with a nickel cobalt manganese (NCM) positive electrode material to which lithium nickel oxide (LNO) is added or mixed In the nickel-cobalt-manganese (NCM) cathode material, the device includes: a heating plate assembled between two or more stacked battery cells to heat the battery cells; and A pressing device pressing the battery cells in a lamination direction to apply pressure to each of the battery cells. 10. The apparatus of claim 9, further comprising: a thermometer that measures the temperature of the battery cells heated by the heating plate; and a pressure gauge that measures the pressure applied to the battery cell by the pressing device. 11. The apparatus of claim 9, wherein the pressing device is combined with the heating plate so that the battery cells are arranged between the heating plates adjacent to each other to be simultaneously Heat and squeeze.